let words=['split','interface','class','array','pop']
let random_index=Math.floor(Math.random()*words.length)
let select_word=words[random_index]
console.log(select_word);
let char_arr=new Array(select_word.length)

char_arr.fill('-')
console.log(char_arr)
while(true){
    let input_char=rs.question('please input one char:')
    console.log(input_char)
    for(let i=0;i<select_word.length;i++)
}